The present invention relates to a pressurized hose coupling which is simple in construction and which uses line pressure to positively engage a flexible hose with the coupling.
Various pressurized air hose couplings are known to couple a pressurized line to a flexible hose. Couplings using nipple ends and lock collars are also known and reference is made to U.S. Pat. No. 3,885,819 as a typical example of prior art couplings that resemble the type of connector to which the present invention relates. However, in that patent, the connector utilizes an end cap to receive the end of the hose fitted over the nipple. The sleeve is also dimensioned to be supported on the end cap. The nipple is provided with ridges as well as the inner surface of the ring. The end cap is also transparent to locate the end of the hose to make sure it remains immovable on the nipple.
In the patent, the sleeve is hand-squeezed forwardly on the hose to connect the hose between its ridges and the ridges of the nipple. The cap is also preferably formed of a thermoplastic material to retain the steel ring thereon by friction fit. Alternatively, the ring could be formed of plastic and the abutment cap formed of steel to obtain the same friction-fit retention. A problem with such design is that because the nipple has ridges thereon, it is sometimes difficult to push the hose entirely over the elongated nipple and locate it into the cap cavity. Also, the ring must be drawn forward towards the enlarged portion of the nipple in order to squeeze the hose tightly thereover while at the same time maintaining the hose snuggly fitted in the end cap. This finger force securement of the ring does not always result in a solid attachment of the flexible hose end over the nipple and could cause the hose to loosen and disconnect during use or cause leakage. Furthermore, the inner surface of the sleeve is not parallel to the nipple outer surface and therefore only a portion of the sleeve is used to clamp the hose and making it more susceptible to leakage.
It is a feature of the present invention to provide a fluid pressure hose coupling which overcomes the above-mentioned disadvantage of the prior art and which is simple to construct and has fewer parts.
Another feature of the present invention is to provide a fluid pressure hose coupling which utilizes the pressure in the supply line to effect the attachment of the flexible hose on the nipple end of the coupling and wherein the hose as well as the hose clamping sleeve is displaced during connection of the hose to the coupling.
Another feature of the present invention is to provide a fluid pressure hose coupling wherein a flexible hose end can be easily slid over a nipple outer smooth surface, easily secured thereover and easily disconnectable from the coupling.
A still further feature of the present invention is to provide a fluid pressure hose coupling wherein the hose pressure in the line acts against the cylindrical hose clamping sleeve to assist in displacing the sleeve over the hose as the sleeve and the hose are pulled together over the nipple.
According to the above features, from a broad aspect, the present invention provides a fluid pressure hose coupling for connecting a flexible hose to a pressurized fluid line. The coupling has a through bore. Connecting means is provided for securing the body to a pressurizable line. The coupling has a cylindrical nipple end section having a circumferentially smooth tapered cone-like outer surface having a larger outer diameter section at a free end thereof. The larger outer diameter is greater than an inner diameter of a flexible hose to slide thereover. The free end has an inwardly tapered circumferential front end wall adapted to assist a hose end inner wall section to be slid over the smooth tapered cone-like outer surface of the nipple end section. A cylindrical hose clamping sleeve is positionable about the nipple end section and has an inwardly tapered inner surface whose diameter is larger at a front end thereof. The inner surface is parallel to the nipple end section outer surface. The cylindrical sleeve when disposed concentrically about the nipple end section with the larger inner diameter at the front end aligned with the larger outer diameter section of the nipple, forms a hose compression gap which is narrower than a wall thickness of an end section of a flexible hose to be slid over the nipple end section whereby positioning the sleeve over the hose end section, when disposed over the nipple end section, and drawing the hose and sleeve towards the free end of the coupling when fluid pressure is applied, causes the sleeve to compress the inner hose section over at least the larger outer diameter section of the tapered outer surface of the nipple end section. The hose end section is disconnected from the nipple end section by removing pressure from the hose and pushing the sleeve rearwardly away from the nipple end section free end out of contact with the hose and pulling the hose out of frictional engagement with the nipple end section.
According to another broad aspect of the present invention there is provided a fluid pressure hose coupling having a cylindrical nipple end section as above-described but wherein a circumferential channel is provided in the body and disposed concentrically about the nipple rearwardly thereof. The channel has an open end facing the free end of the nipple end section and disposed above the larger outer diameter section. A cylindrical hose clamping sleeve having a cylindrical piston end and an opposed inwardly tapered inner clamping surface whose diameter is larger at a front end thereof is also provided. The inner surface is parallel to the nipple end section outer surface. A flexible O-ring is disposed in the channel adjacent an end wall of the channel. Conduit means interconnects the end wall to the through bore. The cylindrical piston end when disposed in the channel against the O-ring forms a hose end receiving gap between the tapered inner surface of the clamping sleeve and the tapered outer surface of the nipple end section to receive an end section of a flexible hose slid over the nipple end section and into the compression gap whereupon, when fluid pressure is applied to the line, pressure will act upon the O-ring through the conduit means and against the cylindrical piston end urging the clamping sleeve together with the hose end section outwardly and causing the hose end section to be compressed between the tapered inner surface of the clamping sleeve and the larger outer diameter section at a free end of the tapered outer surface of the nipple end section which move closer together to diminish the gap a distance less than the thickness of the hose.